DE 198 34 486 A1 describes a method for the protected execution of instructions, wherein, at predefined locations of a sequence of a program, the content of a signature register is compared with a predefined value contained in an instruction of the program.
Namjoo (“Techniques for concurrent testing of VLSI Processor operation”, IEEE Test Conference, 1982, 461-468) discloses a method for detecting errors in the sequence of a program processed by a processor, wherein a path signature is analyzed with regard to a change in the sequence or the type of operation steps of the processor.